Wasn’t there some fairly-recently-discovered parasite that lives on the mouthparts of lobsters that was placed in a new phylum all its own?
Just disputed, or actually changed? IIRC, from your earlier posts on the subject, there is no official body to decide classification at the genus level or higher, but there is for the species level.
There is no official body to decide classification at the species level, either. There are checklists maintained by various organizations, like the American Ornithologists’ Union for birds of North America; but these may differ from other lists such as those maintained by the International Union for the Conservation of Nature (IUCN).
The African Forest Elephant was recommended to be split from the African Bush (or Savanna) Elephant in a paper published in 3001 based on genetic and other evidence. While accepted by many taxonomists, the IUCN African Elephant Specialist Group and others consider the evidence for split to be inadequate.
I do not accept papers published any more than 25 years in the future. Get 500, 600 years out and who knows what kind of cockamamie systematic theory they may have latched onto ;).
Yeah, well that all happens in the next century. We’re talking about now. 
Symbion, in the phylum Cycliophora. There are at least three species; it is a commensal rather than a parasite.
The genus that has only one species is Acinonyx. It only has the species jubatus. Acinonyx jubatus : cheetah
Wikipedia has a list of plant genera with most species. Legumes (Astragalus) top the list with over 3000 species. If one moves up to the Family level instead of Genus, Orchids (Orchidaceae) and Composite Flowers (Asteraceae) would come ahead of Legumes (Fabaceae) — all three families have over 20,000 species. At least three families of beetles have 40,000 species each.
As the Wikipedia article implies, there is some arbitrariness in assigning genus or family boundaries. By the way, another Wikipedia page lists many intermediate grades: cohort between class and order, tribe between family and genus, etc. I don’t know how much in use these are.
As was pointed out over three years ago, there are thousands of genera with only a single species. Given that there are more than one million described species, I would guess that the figure must be in the hundreds of thousands of monospecific genera.
Wow. You can remember the contents to the post of a three-year old thread!
Yeah, I can, but it’s also possible to read them.
Not many species in phylum Placozoa.
Mentioned in post #27.